The present invention relates to an image processing device, an image processing method, an information storage device, and the like.
A stereo matching process is widely known as a technique that calculates the depth (depth information or distance information) using an image. A technique that utilizes a census transform process during the stereo matching process is also known (see JP-A-2003-16427). Ramin Zabih and John Woodfill, “Non-parametric Local Transforms for Computing Visual Correspondence”, Lecture Notes in Computer Science, Vol. 801, Computer Vision-ECCV '94 discloses the census transform process in detail. The census transform process assigns a value (bit data) corresponding to the quantitative relationship between the pixel of interest and each neighboring pixel.
While a known census transform process assigns 0 or 1 corresponding to the quantitative relationship (i.e., difference) between the pixel of interest and each neighboring pixel, Zucheul Lee et al., “Local Disparity Estimation with Three-Moded Cross Census and Advanced Support Weight” discloses a technique that assigns bit data (00) even when the difference is within a noise buffer, and calculates the hamming distance. Zucheul Lee et al., “Local Disparity Estimation with Three-Moded Cross Census and Advanced Support Weight” states that the effect of noise in a flat area can be reduced or suppressed by utilizing the above technique.